Threshold cap



FIG. 1 is a profile view of a threshold cap;

FIG. 2 is a top perspective view thereof; and,

FIG. 3 is a bottom perspective view thereof.

The views not shown form no part of the claimed design. The dash-dot lines in the figures adjacent to the shaded areas represent unclaimed boundaries of the claimed design. The dash-dash lines in the figures represent portions and environmental elements that form no part of the claimed design. 

CLAIM The ornamental design for a threshold cap, as shown and described. 